The present invention relates to a hydraulic system of the kind that is used particularly in motor vehicles, which has a master cylinder with a housing and a piston arranged with axial mobility in the housing. The piston closes off a pressure compartment filled with a hydraulic fluid. When the master cylinder is actuated, the piston is moved by means of a piston rod and as a result, a pressure is applied to the hydraulic fluid. At least one sealing means is arranged between the housing and the piston. The hydraulic system further has a slave cylinder that is connected into the system through a pressure conduit.
A hydraulic system that meets the foregoing description is known for example from DE 100 49 913 A1. In particular in a case where polymer materials are used for the housing and/or piston, this hydraulic system suffers from a problem that is due to transverse forces acting on the piston as a result of swivel movements of the piston. The transverse forces cause abrasive wear on the piston surface and on the housing. As a consequence, if the polymer material of the piston and/or housing is reinforced with glass fibers, some of the fibers can be set free, which has a highly abrasive effect on the seals.